Metal sheathed electrical wire cable

ABSTRACT

A metal sheathed electrical wire cable having a sheath formed of a metal strip. The strip is formed to define a space in which a pair of wires are positioned. The opposite edtes of the strip are joined together and urged downwardly to between the wires to define a substantially fully enclosed raceway for each of the respective wires. The edge portions may comprise flanges facially welded together at a point remote from the wires so as to avoid heat damage to the wire insulation. The sheath may be provided with a longitudinal notch to define a means for facilitating tearing of the sheath to expose desired wire portions.

United States Patent 1191 Kelly 11] 3,745,230 1451 July 10,1973

[ METAL SHEATHED ELECTRICAL WIRE CABLE [76] Inventor: William D. Kelly,12 Blodgett St.,

Clarendon Hills, Ill. 60514 [22] Filed: Jan. 12, 1972 [21] Appl. No.:217,195

Related US. Application Data [63] Continuation-impart of Ser. No.41,007, May 27,

1970, abandoned.

[52] US. Cl. 174/103, 174/113 R, 174/117 R [51] Int. Cl. H01b 7/18 [58]Field of Search 174/103 R, 117 R, 174/72 R, 78, 68 C, 95, 97, 26 R, 27,105 R,

[56] References Cited UNITED STATES PATENTS 9/1965 Jachimowicz 174/105 R3/1969 Kelly 174/103 X 10/1968 Kelly 3,422,214 l/1969 Kelly 174/1031,784,217 12/1930 Berry 174/103 X 1,840,536 l/l932 Shore 174/103 X2,043,044 6/1936 Knoderer 174/103 X Primary Examiner--Bernard A.Gilheany Assistant ExaminerA. T. Grimley AttorneyAxe1 A. Hofgren et al.

[5 7] ABSTRACT A metal sheathed electrical wire cable having a sheathformed of a metal strip. The strip is formed to define a space in whicha pair of wires are positioned. The opposite edtes of the strip arejoined together and urged downwardly to between the wires to define asubstantially fully enclosed raceway for each of the respective wires.The edge portions may comprise flanges facially welded together at apoint remote from the wires so as to avoid heat damage to the wireinsulation. The sheath may be provided with a longitudinal notch todefine a means for facilitating tearing of the sheath to expose desiredwire portions.

21 Claims, 20 Drawing Figures Patented July 10, 1973 2 Sheets-Sheet 2 &B

I METAL SHEATI-IED ELECTRICAL WIRE CABLE CROSS-REFERENCE TO RELATEDAPPLICATIONS This application comprises a continuation-in-part of mycopending application, Ser. No. 41,007, filed May 27, 1970, nowabandoned and entitled Metal Sheathed Electrical Wire Cable.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to electrical wire cable and in SUMMARY OF THE INVENTION Thepresent invention comprehends an improved method of forming anelectrical wire cable wherein the sheath is formed from a flat stripfacilitating insertion of the wires into a partially formed wirereceiving space. The opposite edges of the strip are brought togetherand joined as by welding or other suitable positive joining means todefine a complete enclosure of the wires. The joint is then brought downto between the wires substantially fully to the opposed portion of thesheath whereby the sheath defines substantially completely enclosingraceways for each of the wires with effectively minimum spacingtherebetween for effectively minimum overall size of the cable.

The joint may comprise flanges, formed in the opposite edges of thestrip, which are facially juxtaposed to project away from the tubularwire enclosure during the joining operation. Thus, where the joiningoperation comprises a welding operation, such as a continuous seamwelding operation, the heat of the welding operation is prevented frominjuring the insulation of the wires by virtue of the substantialspacing of the portions being welded from the wires as well as theprojection thereof into the ambient atmosphere. Still further, the jointmay be cooled by a suitable fluid coolant, such as air, immediatelysubsequent to the welding operation to further dissipate thermal energyprecluding damage to the wire insulation.

A longitudinal notch may be provided in the sheath portion opposed tothe joint for facilitated stripping of the sheath from the wires.

The resultant metal sheathed wire cable provides the highly desirableadvantages of a direct path to ground, completely waterproofcharacteristics permitting installation directly in concrete and thelike, high economy of manufacture, and facilitated stripping as formaking electrical connections to the wires and for facilitated groundingof the cable.

The joining operation alternatively may comprise the adhesive bonding ofthe joint flanges. As disclosed, the bonding means may comprise athermosetting resin, such as an epoxy resin.

The flanges may be provided with grooves for receiving a portion of thebonding medium and facilitating the forming of the desired bond betweenthe flanges. The grooves may extend longitudinally along the strip, andin the illustrated embodiment, are provided in each flange for furtherimproved bonding. The resin may be set by suitable thermal transfermeans.

In another form of electrical cable embodying the invention, one or moreadditional wires may be enclosed in the metal sheath outboard of one ofthe wires. Thus, one section of the intumed sheath may define aplurality of raceways for receiving a plurality of wires. As will beobvious to those skilled in the art, such a plurality of wires may besheathed in the section of the cable at each of the opposite sides ofthe joint if so desired.

BRIEF DESCRIPTION OF THE DRAWING Other features and advantages of theinvention will be apparent from the following description taken inconnection with the accompanying drawing wherein:

FIG. 1 is a perspective view of a sheathed electrical wire cableembodying the invention;

FIG. 2 is an end elevation of a metal strip for use in forming thesheath thereof;

FIG. 3 is an end elevation illustrating a first step in the forming ofthe sheath;

FIG. 4 is an end elevation illustrating a second step in the forming ofthe sheath;

FIG. 5 is an end elevation illustratng the placing of the wires withinthe partially enclosing sheath in a third forming step;

FIG. 6 is an end elevation of the arrangement of the assembly during afourth forming step wherein the flange edges are joined;

FIG. 7 is an end elevation illustrating a further forming step; I

FIG. 8 is an end elevation of the sheathed cable;

FIG. 9 is a side elevation illustrating a cross-notching of the sheathfor controlling a stripping operation of an end portion thereof;

FIG. 10 is a side elevation similar to that of FIG. 9 illustrating thearrangement of the cable as upon initiation of the tearing operation;

FIG. 11 is a view illustrating the grounding of the cable;

FIG. 12 is an end elevation illustrating a first step in a modified formof electrical wire cable embodying the invention;

FIG. 13 is an end elevation illustrating a further step in the formingthereof;

FIG. 14 is an end elevation illustrating a further step in the formingthereof;

FIG. 15 is an end elevation illustrating a further step in the formingthereof;

FIG. 16 is an end elevation illustrating a further step in the formingthereof;

FIG. 17 is an end elevation illustrating a further step in the formingthereof;

FIG. 18 is an end elevation illustrating a further step in the formingthereof;

FIG. 19 is a perspective view of the modified form of sheathedelectrical wire cable; and

FIG. 20 is a perspective view of still another modified form of sheathedelectrical cable embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the exemplary embodiment ofthe invention as disclosed in FIGS. 1-1 1 of the drawing, a sheathedelectrical wire cable generally designated is shown to include an outermetal sheath 11 defining a pair of parallel raceways 12 and 13 in whichare received respectively wires 14 and 15 having an outer insulation 16and 17, respectively. Cable 10 comprises an improved electrical wirecable which is waterproof and, thus, is adapted for installation such asin concrete as well as in normal cable installations.

Sheath 11 is preferably formed of a strip of sheet material 18 having afirst mid-portion 19 and opposite edge portions 20 and 21. The stripdefines a longitudinal centerline 22 intermediate edge portions 20 and21. A semi-perforation, or notch, 23, is provided in lower face 24 ofmid-portion 19 to define a tear line in sheath 11 as will be brought outmore fully hereinafter.

As seen in FIGS. 3-8, cable 10 is formed by a succession of steps inwhich strip 18 is caused to define the wire enclosing sheath in a newand improved manner. As shown in FIG. 3, edge portions 20 and 21 mayfirstly be turned from the flat plane of the strip to define downwardlyextending flanged end portions. The insulated wires 14 and 15 may be fedinto overlying juxtaposition to the upper surface of the strip as seenin FIG. 3. The strip is next formed arcuately at portions 25 and 26 tobring the flanged end portions 20 and 21 to a spaced, faciallyjuxtaposed relationship, as shown in FIG. 5. The insulated wires 14 and15 are maintained in the desired spaced relationship in the space 27defined by the partial] wrapped strip. As shown in FIG. 6, the movementof end portions 20 and 21 is continued until the flanged edge portionsare in facial abutment. At this point in the manufacture, arcuateportions 25 and 26 are substantially semi-cylindrical. The abuttingflanged edge portions 20 and 21 are now permanently joined. As shownherein, the edge portions are joined by means for effecting thermalfusion of the edge portions, such as continuous seam roller electrodes28 and As shown in FIG. 6, flanges 20 and 21 project substantially awayfrom space 27 in which wires 14 and 15 are received whereby thermalenergy introduced in effecting the welding is prevented from having adeleterious effect on the insulation of the wires. Not only is the weldpoint substantially spaced from the wires by this means, but also, theweld is exposed to the ambient atmosphere for facilitated dissipation ofheat energy. If desired, suitable blower means 30 may be provided forproviding a coolant fluid, such as air, against the welded flangessubsequent to the welding operation, thereby to further remove heatenergy and prevent damage to the insulation.

The now fully enclosing, partially formed sheath is further formed tocause individual, substantially full enclosure of the respective wires14 and 15 therein, by a movement of the welded flanges 20 and 21downwardly toward mid-portion 19 to a final position as shown in FIG. 8wherein the welded flanges 20 and 21 extend fully downwardly to themid-portion 19 on opposite sides of centerline 22. In bringing thejoined flange portion to this position, the arcuate portions 25 and 26are further extended to define segmentally cylindrical sheath portionsextending over 270 about the respective wires whereby each of raceways12 and 13 is substantially fully enclosed. By referring respectively toFIGS. 7 and 8, it may be seen that the arcuate portions 25 and 26 are,in effect, rolled along bottom portion 19 so as to bring wires 14 and 15more closely together and cause the opposite extremities of portion 19,as shown in FIG. 7, to become arcuate and become portions of thecylindrical portions 25 and 26, as shown in FIG. 8.

The spacing of wires 14 and 15, as shown in FIG. 8, is preselected bythe total width of four thicknesses of the original strip 18. The singleweld joining flanges 20 and 21 thusly serves as means for permittingseparate enclosure of each of raceways 12 and 13 upon the furtherforming of the welded joint, as seen in FIG. 8. As only a single weld isrequired and the wires may be fed into the space 27 laterally throughthe partialy formed sheath, as shown in FIG. 5, high rates of formingspeed may be employed while yet the configuration of the cable may beaccurately controlled. The width of the cable is effectively minimumthereby permitting facilitated bending of the cable both parallel to theplane of the axes of the wires as well as perpendicular thereto.

As seen in FIGS. and 10, when it is desired to remove a portion of thesheath 11, such as for exposing the ends of the wires for making anelectrical connection, a transverse notch 31 may be provided about thesheath across the longitudinal notch 23. The end of the sheath at notch23 may be pried up as shown in FIG. 10, permitting a forceful removal ofthe portion out wardly of notch 31 by the simple manipulation thereof aswith a hand tool, such as a conventional pliers. The notch 31 limits thetearing to define the extent of the uncovered wires.

Sheath 11 may be formed of any suitable material, such as aluminum,galvanized steel, etc. In the illustrated embodiment, where the wiresare 12 ga. plastic insulated wires, the sheath may illustratively beformed of 0.012 inch, or thicker, sheet metal. The forming operation maybe effected by any conventional method, such as roll forming, to providehigh speed manufacture of the cable. The semi-perforation of sheet 18 todefine notch 23 may be effected by any suitable notching means.

Cable 10, by virtue of its improved flexibility, may be provided in coilform in conventional market-size coils.

Additional wires may be included in the sheath and separated from eachother by forming the sheath downwardly therebetween.

As indicated above, a semi-perforation 23 is provided in lower face 24of the strip. As shown in the drawing, the semi-perforation may beprovided by means of a wheel 32 having an annular projection 33 engagingthe lower face 24 of the strip. A corresponding backup roller 34 may beprovided to hold the strip against the action of the semi-perforatingwheel whereby the annular projection 33 forms a longitudinal groove inthe undersurface 24 of the strip. A plurality of such wheels and rollersare positioned longitudinally along the strip so as to further definemeans for aligning the strip accurately longitudinally the lengththereof and thereby facilitating the forming operations. Thus, theannular projection 33a of a second wheel 32a cooperates with a secondroller 34a to hold the strip accurately in longitudinally centeredrelationship in the roll forming operations illustrated therein.Correspondingly successive wheels 32b, 32c, 32d, 32e and 32f may beutilized in conjunction with corresponding cooperating rollers 34b, 3410in the steps illustrated in FIGS. 4 and 5, and alone as undersupports ofthe formed strip in the steps shown in FIGS. 6, 7 and 8 to assist inguiding the formed strip in the various roll forming steps.

Because of the increased accuracy in centering the strip during theforming steps, tolerances in the strip width are not critical. Thus, itis unnecessary to use expensive highly width-controlled strip while yetclose control in the overall configuration of the final cable 10 isreadily obtained.

The use of the semi-perforation groove 23 further permits a facilitatedgrounding of the cable as to an entrance wall 35 of an element such as ajunction box. Thus, as shown in FIG. 11, the cable may be broughtthrough a suitable opening 36 in wall 35 and the end of the sheathstripped back along line 23 to a transverse score line 31 along theupper face thereof as seen in FIGS. 10 and 11. The end of the sheath,however, is not removed from the cable along the underside thereofthereby maintaining an electrical connection between the partiallyremoved sheath end and the remainder of the sheath. The partiallyremoved sheath end may be laid open and folded back along the transverseline 21 which in the lower portion defines a fold line. The folded backsheath end portion 37 may then be facially juxtaposed to the junctionbox wall 35 and suitable screw means 38 passed therethrough to make apositive ground connection between the sheath portion 37 and thejunction box. Thus, grooves 23 and 31 further provide for improvedfacilitated grounding of the sheath in such structures.

Referring now to the embodiment of FIGS. 12-19, a modified form ofsheathed electrical wire cable generally designated 110 is shown toinclude an outer metal sheath 111 receiving a pair of wires 114, 115 ina pair of parallel spaced raceways 112, 113, respectively. Cable 110differs from cable 10 in that the flange edge portions 120 and 121 arejoined by an adhesive bond rather than the fusion weld of cable 10.

Thus, as shown in FIGS. 12-18, the metal strip 118 may firstly beprovided with a plurality of longitudinally extending grooves 142 in oneface of the edges 120 and 121 by means of suitable grooving rollers 143and backup rollers 144, as shown in FIG. 12. The notch 123 may beprovided in the lower face 124 of the strip by means of the wheel 132having a notched projection 133 cooperating with a backup roller 144.

As shown in FIG. 13, the edge portions 120 and 121 are firstly turnedfrom the flat plane of the strip as by suitable wheels 145 pressing theedge portions about a pair of suitable supports 146. The edge portions120 and 121 are then brought upwardly by a pair of rollers 147 engagingthe strip and urging it upwardly about roller guides 148, as shown inFIG. 14. Wheels 145 further comprise means for applying a body ofthermosetting resin 149 to the upper surfaces 150 of the flange portions120 and 121 which may be partially set by suitable heating means, suchas infrared lamps 151 when the flanges are brought upwardly to anapproximatcly horizontal position. The grooves 142 serve to retain theresin on the flange surfaces 150 to assure proper complete bonding ofthe flanges to each other in the completed form of the cable.

As shown in FIG. 15, the metal sheath is further formed in the next stepby suitable further rollers 152 to bring the flanges 120 and 121 intofacially confronting relationship with the wires 114 and 115 partiallyenclosed therein.

As shown in FIG. 16, the flanges may be brought together such as bysuitable rollers 153 which may be suitably heated as by suitable heatingelements 154 to complete the setting of the thermoset plastic, therebyeffectively positively bonding the flanges together to form the desiredjoint generally designated 155. Joint 155 is then brought down betweenthe two wires 114 and 115 in a manner similar to that shown in FIGS. 7and 8 relative to the forming of sheathed cable 10 to form the finalsheathed cable as shown in FIG. 19.

In the illustrated embodiment, the adhesive bond is formed by a suitablebonding plastic, and as discussed above, may comprise a thermosetplastic. One example of an excellent thermoset plastic for this purposecomprises an epoxy resin. An excellent example of such an epoxy resin isbisphenol-A-based epichlorohydrin resin. The resin may be made extremelyflameretardant by using brominated bisphenol-A therein. As will beobvious to those skilled in the art, other suitable plastic materials oradhesive bonding means may be employed within the scope of theinvention.

The sheath 118 may be formed of any suitable material. In theillustrated embodiment, the sheath is formed of a metal, such asaluminum, galvanized steel, etc. Wires 114 and may comprise conventionalinsulated wires, such as plastic insulated wires. The semiperforation123 functions similarly as semi-perforation 23 in cable 10 in permittingfacilitated stripping of the end of the wire when desired.

As discussed previously, where additional wires are desired in thecable, they may be provided as shown in FIG. 20 by forming the sheath218 with additional inturned portions 256 to form a cable generallydesignated 210 having three or more insulated wires therein. Thus, asshown in FIG. 20, a third raceway 257 may be formed outboard of raceway212 by the provision of the inturned portion 256 for carrying a thirdinsulated wire 258 in addition to the first pair of wires 214 and 215disposed on opposite sides of the joint 255. While cable 210 in FIG. 20illustrates the provision of a threewire cable, as will be obvious tothose skilled in the art, any additional number of wires may be providedby the use of additional inturned portions, and such additional wiresmay be provided on either or both sides of the joint 255 as desired. Ineach form, the joint 255 effects a substantially full enclosure of allof the wires irrespective of the numbers of inturned portions 256 as thejoint effectively completes the forming of single envelopes about theentire plurality of wires. As will also be obvious to those skilled inthe art, the joint may comprise the welded joint of cable 10 or thebonded joint of cable 110 as desired within the scope of the invention.

The foregoing disclosure of specific embodiments is illustrative of thebroad inventive concepts comprehended by the invention.

1 claim:

1. An electrical cable comprising:

a one-piece elongated metal sheath defining a longitudinal centerline ina first wall portion, a pair of raceways at opposite sides of saidcenterline comprising opposite side portions of said elongated sheathinturned back to adjacent said longitudinal centerline to define tubularspaced second raceway wall portions, and a longitudinally extendingjoint disposed between said raceways and extending from adjacent saidfirst wall portion outwardly between said raceways comprising the distaledge portion of said sheath returned from said sheath side portions,said distal edge portions being fixedly facially joined; and

insulated electrical wires extending longitudinally in said raceways.

2. The electrical cable of claim 1 wherein said joint comprises a weldedjoint.

3. The electrical cable of claim 2. wherein said joint comprises a seamwelded joint.

4. The electrical cable of claim 1 wherein four substantially equalthicknesses of said sheath are disposed between said raceways.

5. The electrical cable of claim 1 wherein said joint comprises a pairof planar sheath edge portions in facial juxtaposition.

6. The lectrical cable of claim 1 wherein said joint contacts said firstwall portion at opposite sides of said centerline.

7. The electrical cable of claim 1 wherein said joint comprisessubstantially planar edge portions of the sheath and said raceways aredefined by substantially cylindrical portions extending over 270 aboutthe wires.

8. The electrical cable of claim 1 wherein said distal edge portions arefixedly facially joined by an adhesive bond.

9. The electrical cable of claim 1 wherein said distal edge portions arefixedly facially joined by a set thermosetting resin bond.

10. The electrical cable of claim 1 wherein said distal edge portionsare fixedly facially joined by a set epoxy resin bond.

11. The electrical cable of claim 1 wherein said distal edge portionsdefine a plurality of longitudinal grooves and are fixedly faciallyjoined by bonding means provided in said grooves.

12. The electrical cable of claim 1 wherein said sheath further definesa third raceway outwardly of said second raceway, said centerline beingdisposed substantially one-third the width of said cable from the sidethereof adjacent said first raceway to be disposed between said firstand second raceways, and a third insulated wire is disposed coaxially insaid third raceway.

13. The electrical cable of claim 1 wherein said sheath further definesa third raceway outwardly of said second raceway, said centerline beingdisposed substantially one-third the width of said cable from the sidethereof adjacent said first raceway to be disposed between said firstand second raceways, and a third insulated wire is disposed coaxially insaid third raceway, said first wall portion being provided with anoutwardly opening longitudinal groove defining a tear line forfacilitating stripping of the sheath from the wires to expose selectedwire portions, said groove being disposed substantially at saidcenterline.

14. The electrical cable of claim 1 wherein said sheath is furtherinturned to define at least one additional raceway.

15. An electrical cable comprising:

an elongated metal sheath defining a longitudinal centerline in a firstwall portion, a pair of raceways at opposite sides of said centerline,and a longitudinally extending joint disposed between said raceways andextending from a second wall portion opposite said first wall portion tosaid first wall portion whereby said raceways define substantiallyseparated raceways; and

insulated electrical wires extending longitudinally in said raceways,said first wall portion being provided with an outwardly openinglongitudinal groove defining a tear line for facilitating stripping ofthe sheath from the wires to expose selected wire portions.

16. An electrical cable comprising:

an elongated metal sheath defining a longitudinal centerline in a firstwall portion, a pair of raceways at opposite sides of said centerline,and a longitudinally extending joint disposed between said raceways andextending from a second wall portion opposite said first wall portion tosaid first wall portion whereby said raceways define substantiallyseparated raceways; and

insulated electrical wires extending longitudinally in said raceways,the end of said sheath being partially stripped and folded back, andscrew means being provided in association with the stripped end forgrounding the cable.

17. The electrical cable of claim 16 wherein said folded stripped endextends substantially perpendicularly to the longitudinal extent of thecable.

18. An electrical cable comprising:

a one-piece elongated metal strip sheath defining a longitudinalcenterline in a first wall portion, a pair of raceways at opposite sidesof said centerline comprising opposite side portions of said elongatedsheath inturned back to adjacent said longitudinal centerline to definetubular spaced second raceway wall portions, and a longitudinallyextending joint disposed between said raceways and extending fromadjacent said first wall portion outwardly between said racewayscomprising the distal edge portion of said sheath returned from saidsheath side portions;

adhesive means bonding said distal edge portions together whereby saidedge portions are fixedly facially joined; and

insulated electrical wires extending longitudinally in said raceways.

19. The electrical cable of claim 18 wherein said adhesive meanscomprises a thermoset plastic.

20. The electrical cable of claim 18 wherein at least one of said sideedge portions is provided with a groove extending longitudinally of thestrip and receiving a portion of said adhesive means.

21. The electrical cable of claim 18 wherein said side edge portions areprovided with a plurality of grooves extending longitudinally of thestrip and receiving a portion of said adhesive means.

1. An electrical cable comprising: a one-piece elongated metal sheathdefining a longitudinal centerline in a first wall portion, a pair ofraceways at opposite sides of said centerline comprising opposite sideportions of said elongated sheath inturned back to adjacent saidlongitudinal centerline to define tubular spaced second raceway wallportions, and a longitudinally extending joint disposed between saidraceways and extending from adjacent said first wall portion outwardlybetween said raceways comprising the distal edge portion of said sheathreturned from said sheath side portions, said distal edge portions beingfixedly facially joined; and insulated electrical wires extendinglongitudinally in said raceways.
 2. The electrical cable of claim 1wherein said joint comprises a welded joint.
 3. The electrical cable ofclaim 2 wherein said joint comprises a seam welded joint.
 4. Theelectrical cable of claim 1 wherein four substantially equal thicknessesof said sheath are disposed between said raceways.
 5. The electricalcable of claim 1 wherein said joint comprises a pair of planar sheathedge portions in facial juxtaposition.
 6. The electrical cable of claim1 wherein said joint contacts said first wall portion at opposite sidesof said centerline.
 7. The electrical cable of claim 1 wherein saidjoint comprises substantially planar edge portions of the sheath andsaid raceways are defined by substantially cylindrical portionsextending over 270* about the wires.
 8. The electrical cable of claim 1wherein said distal edge portions are fixedly facially joined by anadhesive bond.
 9. The electrical cable of claim 1 wherein said distaledge portions are fixedly facially joined by a set thermosetting resinbond.
 10. The electrical cable of claim 1 wherein said distal edgeportions are fixedly facially joined by a set epoxy resin bond.
 11. Theelectrical cable of claim 1 wherein said distal edge portions define aplurality of longitudinal grooves and are fixedly facially joined bybonding means provided in said grooves.
 12. The electrical cable ofclaim 1 wherein said sheath further defines a third raceway outwardly ofsaid second raceway, said centerline being disposed substantiallyone-third the width of said cable from the side thereof adjacent saidfirst raceway to be disposed between said first and second raceways, anda third insulated wire is disposed coaxially in said third raceway. 13.The electrical cable of claim 1 wherein said sheath further defines athird raceway outwardly of said second raceway, said centerline beingdisposed substantially one-third the width of said cable from the sidethereof adjacent said first raceway to be disposed between said firstand second raceways, and a third insulated wire is disposed coaxially insaid third raceway, said first wall portion being provided with anoutwardly opening longitudinal groove defining a tear line forfacilitating stripping of the sheath from the wires to expose selectedwire portions, said groove being disposed substantially at saidceNterline.
 14. The electrical cable of claim 1 wherein said sheath isfurther inturned to define at least one additional raceway.
 15. Anelectrical cable comprising: an elongated metal sheath defining alongitudinal centerline in a first wall portion, a pair of raceways atopposite sides of said centerline, and a longitudinally extending jointdisposed between said raceways and extending from a second wall portionopposite said first wall portion to said first wall portion whereby saidraceways define substantially separated raceways; and insulatedelectrical wires extending longitudinally in said raceways, said firstwall portion being provided with an outwardly opening longitudinalgroove defining a tear line for facilitating stripping of the sheathfrom the wires to expose selected wire portions.
 16. An electrical cablecomprising: an elongated metal sheath defining a longitudinal centerlinein a first wall portion, a pair of raceways at opposite sides of saidcenterline, and a longitudinally extending joint disposed between saidraceways and extending from a second wall portion opposite said firstwall portion to said first wall portion whereby said raceways definesubstantially separated raceways; and insulated electrical wiresextending longitudinally in said raceways, the end of said sheath beingpartially stripped and folded back, and screw means being provided inassociation with the stripped end for grounding the cable.
 17. Theelectrical cable of claim 16 wherein said folded stripped end extendssubstantially perpendicularly to the longitudinal extent of the cable.18. An electrical cable comprising: a one-piece elongated metal stripsheath defining a longitudinal centerline in a first wall portion, apair of raceways at opposite sides of said centerline comprisingopposite side portions of said elongated sheath inturned back toadjacent said longitudinal centerline to define tubular spaced secondraceway wall portions, and a longitudinally extending joint disposedbetween said raceways and extending from adjacent said first wallportion outwardly between said raceways comprising the distal edgeportion of said sheath returned from said sheath side portions; adhesivemeans bonding said distal edge portions together whereby said edgeportions are fixedly facially joined; and insulated electrical wiresextending longitudinally in said raceways.
 19. The electrical cable ofclaim 18 wherein said adhesive means comprises a thermoset plastic. 20.The electrical cable of claim 18 wherein at least one of said side edgeportions is provided with a groove extending longitudinally of the stripand receiving a portion of said adhesive means.
 21. The electrical cableof claim 18 wherein said side edge portions are provided with aplurality of grooves extending longitudinally of the strip and receivinga portion of said adhesive means.